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This article explores the history of the invasive plant species Rhodomyrtus tomentosa in Florida and Hawaii. The authors stress the importance of understanding the biology and introduction of such species to develop effective regulation strategies. They trace the importation history of R. tomentosa through taxonomic research and historical records, including horticultural catalogs and herbarium specimens. The article provides information on the taxonomy, common names, and earliest record of R. tomentosa in Florida. It also discusses the distribution and cultivation of the plant in specific counties during the late 19th and early 20th centuries. Ongoing genetic investigations are being conducted to determine the presence of different varieties and hybrids in Florida. The article references two documents, one providing an inventory of plant materials introduced by the Bureau of Plant Industry in 1937, and another being a publication by R. Wight in 1846. [Extracted from the article]

Multiple importations of Lilioceris cheni, a defoliating beetle of the invasive air potato plant, were received by the ARS-Invasive Plant Research Laboratory from 2002 to 2012. The last two, in 2011 (China) and 2012 (Nepal), formed the basis of two colonies from which releases were made into six Southeastern U.S. States. Colony populations were examined using the mitochondrial COI sequence. Phylogenetics, evolutionary divergence, a haplotype network, population statistics, and migration models were generated for the two colonies, countries of origin, and the inferred populations (clades). Phylogenetics eliminated the possibility of cryptic speciation and alleviated the need for host-range testing of the 2012 Nepalese samples. Evolutionary divergence showed the Chinese colony was 1.65X as divergent as the Nepalese, but one Nepalese clade was the most distinctly different of all clades. AMOVA showed most (>70%) genetic variation resided within rather than between colonies. In contrast, AMOVAs showed high levels (>61.5%) of genetic variation between underlying clades with proportionally less variation within. The haplotype network showed broad agreement with the phylogeny. Clade C, from China, displayed the largest number of haplotypes and the largest mutation-scaled effective population size in MIGRATE software. The best MIGRATE models indicated that migration and descent followed the order of phylogenetic descent. The results suggest that the genetic diversity being offered to the adventive range by these very divergent colonies (and clades) is large and should support great ecological flexibility. [ABSTRACT FROM AUTHOR]

Understanding the origins and genetic relationships of invasive, non-native species is critical to informing conservation and management practices. Pistia stratiotes is one such species—a pantropical floating plant that is problematic in many regions of the world, including Florida, USA. Questions surrounding the origins of P. stratiotes populations in Florida and elsewhere prompted a molecular investigation using five chloroplast and one mitochondrial DNA sequences. A total of 154 samples were collected from 14 countries. The sequence data was analyzed using haplotype network analysis, maximum likelihood phylogenetics and species delimitation tools. These data show that P. stratiotes comprises a minimum of seven distinct haplotypic clades worldwide, three of which differ enough to likely represent different species. Florida, which was more heavily sampled than other regions of the world, contains four of the clades—one of which shows evidence of being pan-Caribbean with sufficient variation to suggest regional (including Florida) nativity. A second clade, present in the U.S. Gulf States and California, may be native within this range, however more sampling is needed to fully describe its distribution and nativity. Another clade, predominant in southern Florida and the St. Johns River, likely originated in South America. Results are discussed in the broader context of the effects of cryptic species on weed management, including biological control efforts. [ABSTRACT FROM AUTHOR]

Predators can severely limit or prevent the establishment of newly introduced biological control agents. Identifying key predators and quantifying their impacts, however, has often proved difficult, especially in cases where the biological control agent has low establishment or detectability. We used molecular gut content analysis to identify predators feeding on Neomusotimaconspurcatalis Warren (Lepidoptera: Crambidae), a biological control agent for Lygodiummicrophyllum (Cavanilles) R Brown (Lygodiaceae), an invasive weed in Florida, USA. We developed DNA primers specific to N.conspurcatalis, and conducted laboratory feeding trials to confirm that agent DNA could be detected in predator guts through PCR amplification. We then released N.conspurcatalis at three L.microphyllum infested sites and one week later conducted field surveys for predators. Our experimental field survey indicated that predatory arthropods were attracted to the immediate locations of N.conspurcatalis releases. A total of 351 predatory arthropods were collected from L.microphyllum infested sites, representing a broad taxonomic range. At least 33% of individuals from all 13 taxa analyzed had fed on N.conspurcatalis. Of the four predator functional groups encountered, spiders were the most numerous, and appeared to be the most important group based on predation rate. Our results can inform the N.conspurcatalis release program, providing guidance on avoiding generating predation hotspots, and facilitating predictions about where and when N.conspurcatalis releases are most likely to result in establishment. Additionally, we highlight the potential of molecular gut content analysis to improve our understanding of the effects of predators on newly introduced classical biological control agents. [ABSTRACT FROM AUTHOR]

Aim: Understanding the genetic structure of plants in their native range is crucial when reconstructing the invasion history of weeds. This information allows researchers to pinpoint the provenance of invasive plants and to test the importance of genetic admixture in facilitating invasion success. We assessed genetic structuring across the native range of A. auriculiformis, to determine whether genetic admixture contributes to the success of this weed in its introduced range, and test for rapid adaptation to environmental conditions in the invasive lineage. Location: Australia, Papua New Guinea, Florida. Taxon: Earleaf acacia. Methods: We sampled A. auriculiformis from across its entire native distribution (northern Australia, Papua New Guinea) and its invasive range in Florida, and used genotyping by sequencing (GBS) to assess population structuring. Results: Principal component analysis, based on 9591 single‐nucleotide polymorphisms, indicated significant differentiation among samples from Papua New Guinea, the Northern Territory (Australia) and north Queensland (Australia). Florida samples also formed a distinct cluster, with these samples most closely related to samples from the Northern Territory. These results indicate that the Florida A. auriculiformis lineage most likely originates from the Northern Territory, with no evidence that plants were introduced from different parts of the native range. We found evidence of allelic shifts in the Florida population, suggesting rapid adaptation to environmental conditions may contribute the success of the invasive lineage. Main conclusions: Two well‐known biogeographic barriers—the Carpentaria Gap and Torres Strait—have caused genome‐wide divergence among A. auriculiformis plants from north Queensland, Northern Territory and Papua New Guinea. The taxonomic status of these allopatric populations should be further assessed. As the Florida lineage originated in the Northern Territory, the search for potential biological control agents should be focused in this region. Our results also demonstrate how artificial selection and strong genetic drift may cause introduced plants to have a unique genetic make‐up not found in the native range. [ABSTRACT FROM AUTHOR]

Three colonies ofNeostromboceros albicomus, a candidate biological control agent ofLygodium microphyllum, were barcoded using theD2expansion domain, to determine which of two biotypes they represented. The first colony, collected in 2005 and 2007, was used for the initial host range testing. Colonies collected in 2012 and 2014 are currently being used to finalise this testing. All three colonies were collected in Trat Province, Thailand and all three populations show identical sequences to theN. albicomusbiotype which prefersL. microphyllumas its host plant. TheN. albicomusbiotype that usesL. flexuosumas its host plant differs by a single nucleotide, a difference which may reflect cryptic speciation. [ABSTRACT FROM AUTHOR]

The Australian psyllidBoreioglycaspis melaleucaeis a biological control agent ofMelaleuca quinquenerviain Florida (USA) but was observed attackingM. quinquenerviatrees in southern California (USA). Genotyping revealed the California population matched three of eight Australian haplotypes and all three Florida haplotypes. It remains unclear if the California psyllid population arrived directly from Australia or via Florida. [ABSTRACT FROM PUBLISHER]